Re: Indexes on array columns

contrib/intarray might help you

Oleg
On Wed, 15 Mar 2006, karly(at)kipshouse(dot)org wrote:

> On Wed, Mar 15, 2006 at 09:36:04AM -0700, Brendan Duddridge wrote:
>> Hi,
>>
>> Is it possible to put an index on an array column?
>
> Apparently yes (I just did it as a test). However, consider the
> following from the manual.
>
> Tip: Arrays are not sets; searching for specific array elements
> may be a sign of database misdesign. Consider using a separate
> table with a row for each item that would be an array element. This
> will be easier to search, and is likely to scale up better to large
> numbers of elements.[1]
>
> Arrays are attractive, but it seems they most often aren't the best
> solution. FOr instance, I beleive I read somewhere that the index
> will be on the whole array, and the individual elements are not
> indexed, so
>
> WHERE ary = {foo,bar}
>
> might benefit from your index, but
>
> WHERE 'foo' = ANY(ary)
>
> probably wouldn't. At least that's the impression I got from
> reading the archives of this list. I haven't done any testing of
> it.
>
>
> -karl
>
>
>
> 1. http://www.postgresql.org/docs/8.0/interactive/arrays.html#AEN5491
>
>>
>> Thanks,
>>
>> ____________________________________________________________________
>> Brendan Duddridge | CTO | 403-277-5591 x24 | brendan(at)clickspace(dot)com
>>
>> ClickSpace Interactive Inc.
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>>
>> http://www.clickspace.com
>>
>
>
>
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Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: oleg(at)sai(dot)msu(dot)su, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83